1. Field of the Invention.
The invention relates in general to electromechanical timers and in particular to a timer in which the bussing is held in place positively upon insertion into the timer housing thereby simplifying and adding flexibility to the manufacturing process.
2. Description of the Related Art.
Electromechanical timers have been used to provide programmed control of appliance functions for more than half a century. Such timers generally comprise a motor-driven cam and electrical switches responsive to the cam for controlling the appliance functions. The cam and switches are mounted in a timer housing, and electrical terminals connected to the switches extend from the housing. Generally, the timer also includes electrical busses which connect some of the terminals in order to distribute the electrical power and timing signals appropriately for the timing function and to provide for more efficient connection to the appliance components to be controlled by the timer. Examples of such electrical bussing is disclosed in U.S. Pat. Nos. 4,567,654 on an invention of Ernest F. Kloenne and Garry A. Stout, 4,517,426 in the name of James 0. Edwards and Charles Malone, 3,809,831 in the names of George A. Godwin and William E. Wagle, and 3,771,102 on an invention of Stephen F. Murray and Harold T. Simmons. In the Edwards patent, the busses are held in place by spot welding to the terminal blades. This is time consuming and requires special jigs to hold the busses during assembly. It generally requires the terminals to be inserted before the bussing, which reduces the flexibility of the manufacturing process. The Murray and Godwin patents disclose bussing that includes spring elements that hold the bussing in place, at least temporarily, during the manufacturing process. However, in each of these the bussing spring force acts only directly against the terminals, thus the terminal should be in place before the bussing is added, otherwise dislodgement of busses can occur. In the apparatus of the Kloenne patent, this disadvantage is avoided by a construction which traps but does not hold the busses in place before insertion of the terminals. Flexibility is lost however in this instance because the busses cannot be added or easily removed after the terminals are inserted. U.S. Pat. Nos. 3,212,048 in the names of Richard A. Rosenberg and Martin A. Mittler, and 3,353,138 in the name of Winfield Warren Loose disclose other bussing systems that may be of interest. However in addition to the disadvantages discussed in relation to the Murray and Godwin patents, they do not permit skipping of terminals by a bus and thus their applicability to an electromechanical timer bussing system is doubtful.